Wide range 8ps incremental resolution time interval generator based on FPGA technology

Accurate generation of picosecond-resolution wide-range time intervals has become a necessity for the characterization of time-to-digital converters involved in time resolved imaging. This paper presents the design and measurement of a time interval generator based on FPGA technology. Although it can be employed in different automatic test setups, it has been designed to characterize an array of time-to-digital converters. It can work as periodic pulse/ frequency generator but also as a digital-to-time converter. The accuracy of periodic pulse generator is around 20ps RMS jitter over a time range of 600ps to 33ns. The incremental time resolution is 8ps and the repetition rate is up to 2MHz. The accuracy of the digital-to-time converter is less than 0.8LSB DNL and 2LSB INL, whilst the time resolution is 27ps. Full characterization of the module is reported including a comparison with state-of-the-art instruments in this field.